ISL29044A Datasheet, PDF (1/2 Pages) Intersil Corporation – Low Power Ambient Light and Proximity Sensor with Internal IR-LED and Digital Output

Low Power Ambient Light and Proximity Sensor with
Internal IR-LED and Digital Output
ISL29044A
The ISL29044A is an integrated ambient and infrared
light-to-digital converter with a built-in IR LED and I²C Interface
(SMBus Compatible). This device uses two independent ADCs
for concurrently measuring ambient light and proximity in
parallel. The flexible interrupt scheme is designed for minimal
micro-controller utilization.
For ambient light sensor (ALS) data conversions, an ADC
converts photodiode current (with a light sensitivity range up to
3200Lux) in 100ms per sample. The ADC rejects 50Hz/60Hz
flicker noise caused by artificial light sources.
For proximity sensor (Prox) data conversions, the built-in driver
turns on an internal infrared LED and the proximity sensor ADC
converts the reflected IR intensity to digital. This ADC rejects
ambient IR noise (such as sunlight) and has a 547μs
conversion time.
The ISL29044A provides low power operation of ALS and
proximity sensing with a typical 133μA normal operation
current (108μA for sensors and internal circuitry, ~25μA for
LED) with 220mA current pulses for a net 100μs, repeating
every 800ms (or under).
The ISL29044A uses both a hardware pin and software bits to
indicate an interrupt event has occurred. An ALS interrupt is
defined as a measurement that is outside a set window. A
proximity interrupt is defined as a measurement over a
threshold limit. The user may also require that both ALS/Prox
interrupts occur at once, up to 16 times in a row before
activating the interrupt pin.
The ISL29044A is designed to operate from 2.25V to 3.63V
over the -40°C to +85°C ambient temperature range. It is
packaged in a clear, lead-free 8 Ld ODFN package.
Features
• Internal LED + Sensor = complete solution
• Works under all light sources including sunlight
• Dual ADCs measure ALS/Prox concurrently
• <1.0μA Supply current when powered down
• Temperature compensated
• Pb-Free (RoHS compliant)
Intelligent and Flexible Interrupts
• Independent ALS/Prox interrupt thresholds
• Adjustable interrupt persistency
- 1/4/8/16 consecutive triggers required before interrupt
Applications
• Display and keypad dimming adjustment and proximity
sensing for:
- Mobile devices: Smart phone, PDA, GPS
- Computing devices: Laptop PC, Netbook, Tablet PC
- Consumer devices: LCD-TV, digital picture frame, digital
camera
- Industrial and medical light and proximity sensing
Related Literature
• See AN1436, “Proximity Sensors”
V_LED
V_PULLUP
I²C SLAVE 0
5 _{LED- LED+} 4
6 _{IRDR GND} 3
7 _{INT SCL} 2
8 _{SDA VDD} 1
ISL29044A C1
0.1µF
C3
0.1µF
R1
RES1
VDD
I²C SLAVE 1 I²C SLAVE_n
C2
1µF
SCL
SCL
SDA
SDA
I²C-DIAGRAM I²C-DIAGRAM
R2
RES1
R3
RES1
I²C MASTER
SCL
SDA
INT
CONTROLLER
FIGURE 1. TYPICAL APPLICATION
April 19, 2013
1
FN8419.1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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